Semen or seminal fluid or seminal plasma is the fluid ejaculated from the penis at sexual climax. Each ejaculate may contain 300 - 500 million spermatozoa suspended in a fluid secreted by the prostate gland and seminal vesicles with a small contribution and certain enzymes. It provides a fluid medium for transport of sperms, nourishes & activates sperms, lubricates the reproductive tract of females and neutralizes the acidity of the vagina of females to protect the sperms.